Centrifugal pump

ABSTRACT

A centrifugal pump includes a rotating blade member including an impeller member and a rotor magnet provided under the impeller member, a metallic main body casing in which the rotating blade member is accommodated, and a coil portion configured to rotate the rotating blade member. The coil portion is disposed to be located in a periphery of the rotor magnet. The metallic main body casing includes an upper main body casing, and a lower main body casing which is fixed to the upper main body casing. The lower main body casing includes a blade accommodating portion, which extends horizontally from an outer periphery of the lower main body casing to an inner periphery side, and a rotor magnet accommodating portion, which extends downwardly from the blade accommodating portion.

The present application claims priority to Japanese Application No. 2014-149079 filed Jul. 22, 2014 and Japanese Application No. 2015-083843 filed Apr. 16, 2015, which are both incorporated herein by reference.

TECHNICAL FIELD

Embodiments relate to a centrifugal pump to circulate the fluid in the closed circuit, for instance, refrigerant used for refrigerant circulation circuits such as air conditioners and freezers, and cooling water etc. used for cooling circulation circuits such as parts and apparatuses that generate heat.

Moreover, this centrifugal pump is a centrifugal pump in which the resisting pressure and airtight are required.

BACKGROUND ART

Conventionally, as such a centrifugal pump to circulate the liquid, Patent Document 1 (JP 2003-13878, A) is open to the public.

In this Patent Document 1, a centrifugal pump is disclosed, in which the structure of the impeller member is improved so that a plurality of passage portion that extends radially from the center of the impeller member is formed.

As a result, the circulation amount change of cooling water is low, and the change in the cooling capability is not generated easily.

Moreover, in Patent Document 2 (JP 2003-161284, A), the impeller member is disposed wherein a plurality of the blade is formed to the outer periphery and the rotor magnet is provided to the inner periphery.

In addition, the motor stator is disposed to the inner periphery side of the rotor magnet.

As a result, a thin centrifugal pump that can achieve an efficient cooling is disclosed.

SUMMARY Problems to be Solved

However, in such a conventional centrifugal pump, it is not a strong airtight structure.

For instance, cooling water such as internal combustion engines; and fluid of refrigerant etc. used for refrigerant circulation circuits etc. such as air conditioners and freezers; and combustibility fluid; and fluid having toxicity etc. are circulated in closed circuit.

In such case, there are problems in the resisting pressure and the air-tight of the centrifugal pump.

Moreover, in the structure of a conventional centrifugal pump, the coil portion that is the motor stator cannot be detached.

Therefore, in order to use it for the centrifugal pump in which the resisting pressure and the air-tight are required, even if the casing and the piping, etc. of metallic are used, it cannot be fixed by heating such as the welding, the brazing, and the adhesion, etc.

In addition, the bearing of the impeller member consists of bearing which is disposed to one side of the shaft of the impeller member.

Therefore, it is unstable, and there are problems in durability and quietness.

Moreover, in such a centrifugal pump having the conventional structure, the bearing is in the fluid, and the lubricant cannot be used.

Therefore, the axial member and the impeller member are wear-out and damaged by rotating of the impeller member.

As a result, the rattling and the decentering are caused in the impeller member.

It is difficult to keep the pump performance having the predetermined objects.

The embodiments consider such a current state and provide an excellent centrifugal pump in the pump performance.

In the centrifugal pump, it can be fixed by heating such as the welding, the brazing, and the adhesion, etc. and the metal casing and the piping having high airtight can be used.

Moreover, the centrifugal pump can be used for the centrifugal pump, in which for instance, a refrigerant, a combustible fluid, and the fluid having toxicity are circulated in the closed circuit, and in which the resisting pressure, airtight, and resistance to corrosion are required.

Solution to Problem

The invention was invented to achieve the problem and the purpose in the above-mentioned prior art,

the centrifugal pump comprises:

a rotating blade member including an impeller member and a rotor magnet provided under the impeller member,

a metallic main body casing in which the rotating blade member is accommodated, and

a coil portion configured to rotate the rotating blade member, wherein the coil portion is disposed to be located in a periphery of the rotor magnet,

the metallic main body casing comprising;

an upper main body casing, and

a lower main body casing which is fixed to the upper main body casing,

the lower main body casing comprising;

a blade accommodating portion, which extends horizontally from an outer periphery of the lower main body casing to an inner periphery side, and

a rotor magnet accommodating portion, which extends downwardly from the blade accommodating portion.

By composing like this, the main body casing has a shape, which comprises:

the upper main body casing, and

the lower main body casing which is fixed to the upper main body casing,

the lower main body casing comprising;

the blade accommodating portion, which extends horizontally from outer periphery of the lower main body casing to the inner periphery side, and

the rotor magnet accommodating portion, which extends downwardly from the blade accommodating portion.

Therefore, in the space formed between the upper main body casing and the lower main body casing fixed to the upper main body casing,

the rotating blade member, which includes the impeller member and the rotor magnet provided under the impeller member, can be accommodated in compact.

Moreover, the coil portion configured to rotate the rotating blade member is provided. The coil portion is disposed to be located in the periphery of the rotor magnet.

Therefore, the magnetic path, which is disposed to be located in the periphery of the rotor magnet, is generated by energizing the coil portion.

As a result, through the rotor magnet accommodating portion of the lower main body casing, it effects to the rotor magnet provided under the impeller member.

As a result, stably rotating of the rotating blade member can be attained.

Therefore, the operation loss of the driving motor (the coil portion and the rotor magnet) is never caused, and a centrifugal pump which has an excellent pump performance can be provided.

Moreover, the upper main body casing and the lower main body casing that compose a metallic main body casing, for instance, can be fixed by heating such as the welding, the brazing, and the adhesion, etc., so that they can be fixed in the sealing state.

That is, it is a structure in which a joint method with high airtight and maintenance strength such as the welding and the brazing can be applied to these connecting portions.

Therefore, fixing by heating such as the welding, the brazing, and the adhesion, etc. can be applied.

As a result, the centrifugal pump, in which for instance, a refrigerant, a combustible fluid, and the fluid having a toxicity are circulated in the closed circuit, and in which the resisting pressure, airtight, and resistance to corrosion are required, can be provided.

Moreover, a centrifugal pump is characterized in that

-   -   the lower main body casing comprises a metallic press molding         article, and

the lower main body casing comprises a nonmagnetic metal.

Like this, the lower main body casing comprises a metallic press molding article.

As a result, the lower main body casing (i.e. rotor casing) having the complicated shape,

in which the blade accommodating portion that extends horizontally from outer periphery of the lower main body casing to the inner periphery side, and

in which the rotor magnet accommodating portion that extends downwardly from the blade accommodating portion, can be made easily, high-quality, and at a low price.

Moreover, the lower main body casing comprises the nonmagnetic metal.

As a result, the magnetic path generated by energizing the coil portion, which is disposed to be located in the periphery of the rotor magnet, is not obstructed.

Therefore, through the rotor magnet accommodating portion of the non-magnetic lower main body casing, it effects on the rotor magnet provided under the impeller member.

As a result, stably rotating of the rotating blade member can be attained.

Therefore, the operation loss of the driving motor (the coil portion and the rotor magnet) is never caused, and an excellent centrifugal pump in the pump performance can be offered.

In this case, as for the nonmagnetic metal, though it is not especially limited, for instance, copper, stainless steel, aluminum, and brass, etc. are exemplified.

Moreover, the centrifugal pump is characterized in that the nonmagnetic metal comprises an austenitic stainless steel.

Thus, if the nonmagnetic metal comprises the austenitic stainless steel, the upper main body casing and the lower main body casing that compose a metallic main body casing, for instance, can be fixed by heating such as the welding, the brazing, and the adhesion, etc., so that they can be fixed in the sealing state.

Moreover, if it is the austenitic stainless steel, it is excellent in the drawing property and the mechanical strength.

As a result, the lower main body casing (i.e. rotor casing) having the complicated shape,

in which the blade accommodating portion that extends horizontally from outer periphery of the lower main body casing to the inner periphery side, and

in which the rotor magnet accommodating portion that extends downwardly from the blade accommodating portion,

can be made easily by press work, high-quality, and at a low price.

Moreover, the austenitic stainless steel is excellent in the drawing property, so that the thickness of the lower main body casing can be thinned.

As a result, the magnetic path generated by energizing the coil portion, which is disposed to be located in the periphery of the rotor magnet and which rotates the rotating blade member, is not obstructed.

Therefore, through the rotor magnet accommodating portion of the non-magnetic lower main body casing, it effects on the rotor magnet provided under the impeller member.

As a result, stably rotating of the rotating blade member can be attained.

Therefore, the operation loss of the driving motor (the coil portion and the rotor magnet) is never caused, and an excellent centrifugal pump in the pump performance can be offered.

Moreover, the austenitic stainless steel is also excellent in corrosion resistance.

As a result, the centrifugal pump, in which for instance, a refrigerant, a combustible fluid, and the fluid having a toxicity are circulated in the closed circuit, and the resisting pressure, airtight, and resistance to corrosion are required, can be provided.

Moreover, the centrifugal pump is characterized in that the austenitic stainless steel includes 10.5% or more of the content of nickel.

That is, in case that the lower main body casing having the complicated shape,

in which the blade accommodating portion that extends horizontally from an outer periphery of the lower main body casing to the inner periphery side, and

in which the rotor magnet accommodating portion that extends downwardly from the blade accommodating portion, is made,

as mentioned above, it is desirable so that the lower main body casing comprises the austenitic stainless steel in order to make it easily, high-quality, and at a low price.

However, for instance, in a usual austenitic stainless steel, such as SUS304 having 8% of Ni content, which is called 18-8 stainless steel, if the deformation processing is performed such as the drawing etc., the stress induced martensite is generated.

As a result, there is a case that it becomes martensite and is magnetized.

Therefore, the magnetic path generated by energizing the coil portion, which is disposed to be located in the periphery of the rotor magnet and which rotates the rotating blade member, is obstructed, by the lower main body casing that is magnetized.

As a result, the function to the rotor magnet provided under the impeller member is obstructed through the rotor magnet accommodating portion of the lower main body casing.

Therefore, the operation loss of the driving motor (the coil portion and the rotor magnet) is caused so that the pump performance is decreased.

On the contrary, the austenitic stainless steel includes 10.5% or more of the content of nickel.

As a result, even if the deformation processing is performed such as the drawing etc., the stress induced martensite is not generated easily.

Therefore, it is avoided to become martensite and to be magnetized.

As a result, the magnetic path generated by energizing the coil portion, which is disposed to be located in the periphery of the rotor magnet, is not obstructed.

Therefore, through the rotor magnet accommodating portion of the non-magnetic lower main body casing, it effects on the rotor magnet provided under the impeller member.

As a result, stably rotating of the rotating blade member can be attained.

Therefore, the operation loss of the driving motor (the coil portion and the rotor magnet) is never caused, and an excellent centrifugal pump in the pump performance can be offered.

Moreover, the centrifugal pump is characterized in that the austenitic stainless steel having 10.5-16% of the content of nickel.

If the content of the nickel of the austenitic stainless steel is within such the range, even if the deformation processing is performed such as the drawing etc., the stress induced martensite is not generated easily.

Therefore, it is avoided to become martensite and to be magnetized.

As a result, it can be avoided that the function to the rotor magnet provided under the impeller member is obstructed through the rotor magnet accommodating portion of the lower main body casing.

Therefore, the operation loss of the driving motor (the coil portion and the rotor magnet) is not caused so that the pump performance is not decreased.

If the content of the nickel is below 10.5%, if the deformation processing is performed such as the drawing etc., the stress induced martensite is generated.

As a result, it becomes martensite and is magnetized. Oppositely, if the content of the nickel exceeds 16%, the cost rises since the nickel is expensive.

As for such an austenitic stainless steel having 10.5-16% of the content of the nickel, it is not limited particularly.

However, according to the usage of the centrifugal pump, in consideration of the corrosion resistance, the processing, and the mechanical strength, etc., for instance, it may include the austenitic stainless steel selected from SUS305, SUS308, SUS309, SUS316, and SUS317.

Moreover, a centrifugal pump comprising:

a metallic suction side coupling member, which is provided to connect to the main body casing to introduce fluid into the impeller member,

a metallic discharge side coupling member, which is provided to connect to the main body casing to exhaust fluid by rotating the impeller member, and

a blade casing, which partitions an interior space formed by the upper main body casing and the lower main body casing so that

a fluid introducing passage is formed at an upper portion, and

a rotating accommodating space that accommodates the rotating blade member is formed at a lower portion.

By composing like this, the joint portion between the metallic main body casing (the upper main body casing or the lower main body casing or both thereof) and the blade casing, for instance, can be fixed by heating such as the welding, the brazing, and the adhesion, etc., so that they can be fixed in the sealing state.

Moreover, the joint portion between the metallic suction side coupling member and the main body casing, and the joint portion between the discharge side coupling member and the main body casing, for instance, can be fixed by heating such as the welding, the brazing, and the adhesion, etc., so that they can be fixed in the sealing state.

That is, it is a structure in which a joint method with high airtight and maintenance strength such as the welding and the brazing can be applied to these connecting portions.

Therefore, it can be fixed by heating such as the welding, the brazing, and the adhesion, etc. and the metal casing and the piping having high airtight can be used.

Moreover, the centrifugal pump, in which for instance, a refrigerant, a combustible fluid, and the fluid having a toxicity are circulated in the closed circuit, and in which the resisting pressure, airtight, and resistance to corrosion are required, can be offered.

Moreover, the blade casing,

which partitions an interior space formed by the upper main body casing and the lower main body casing so that

a fluid introducing passage is formed at an upper portion, and

a rotating accommodating space that accommodates the rotating blade member is formed at a lower portion,

is provided.

As a result, the path of the fluid can be easily formed.

Advantageous Effects

The main body casing has a shape, which comprises:

the upper main body casing, and

the lower main body casing which is fixed to the upper main body casing,

the lower main body casing comprising;

the blade accommodating portion, which extends horizontally from outer periphery of the lower main body casing to the inner periphery side, and

the rotor magnet accommodating portion, which is extended downwardly from the blade accommodating portion.

Therefore, in the space formed between the upper main body casing and the lower main body casing fixed to the upper main body casing,

the rotating blade member, which includes the impeller member and the rotor magnet provided under the impeller member, can be accommodated in compact.

Moreover, the coil portion configured to rotate the rotating blade member is provided, wherein the coil portion is disposed to be located in the periphery of the rotor magnet.

Therefore, the magnetic path is generated by energizing the coil portion, which is disposed to be located in the periphery of the rotor magnet.

As a result, through the rotor magnet accommodating portion of the lower main body casing, it effects to the rotor magnet provided under the impeller member.

As a result, stably rotating of the rotating blade member can be attained.

Therefore, the operation loss of the driving motor (the coil portion and the rotor magnet) is never caused, and a centrifugal pump which has an excellent pump performance can be provided.

Moreover, the upper main body casing and the lower main body casing that compose a metallic main body casing, for instance, can be fixed by heating such as the welding, the brazing, and the adhesion, etc., so that they can be fixed in the sealing state.

That is, it is a structure in which a joint method with high airtight and maintenance strength such as the welding and the brazing can be applied to these connecting portions.

Therefore, fixing by heating such as the welding, the brazing, and the adhesion, etc. can be applied.

As a result, the centrifugal pump, in which for instance, a refrigerant, a combustible fluid, and the fluid having a toxicity are circulated in the closed circuit, and in which the resisting pressure, airtight, and resistance to corrosion are required, can be provided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a longitudinal sectional view of an embodiment of the centrifugal pump.

FIG. 2 is a partial enlarged sectional view of the centrifugal pump of FIG. 1.

FIG. 3 is a schematic cross-sectional view, in which disposing of the internal space S1, the fluid introducing passage 84, and the rotating accommodating space S2 of the centrifugal pump of FIG. 1.

DESCRIPTION OF EMBODIMENTS

Hereafter, embodiments (Embodiments) are described in the detail or more on the basis of the drawing.

Embodiment 1

FIG. 1 is a longitudinal sectional view of an embodiment of the centrifugal pump.

FIG. 2 is a partial enlarged sectional view of the centrifugal pump of FIG. 1.

FIG. 3 is a schematic cross-sectional view, in which disposing of the internal space S1, the fluid introducing passage 84, and the rotating accommodating space S2 of the centrifugal pump of FIG. 1.

In addition, in the specification, the wordings, such as “upper side”, “upper portion”, “upper”, “lower side”, “lower portion”, and “lower” which show vertical direction, indicate the vertical direction in each drawing.

Moreover, they indicate a relative position of each member and they do not indicate absolute position.

In FIG. 1-FIG. 2, reference numeral 10 shows exemplary centrifugal pump as a whole.

For convenience' sake of the clarification in FIG. 3, a main body casing 34, an upper main body casing 36, a lower main body casing 48, a blade casing 68, a suction side coupling member 42, and a discharge side coupling member 46 are only shown and other members are omitted.

As shown in FIG. 1-FIG. 2, a centrifugal pump 10 comprises a rotating blade member 12.

As shown in FIG. 1-FIG. 2, this rotating blade member 12 comprises a plurality of blade members 16, which radially extends in the direction of the outer periphery in an upper part of a circular tube bearing portion 14.

In addition, the number of sheets of this blade member 16 may be elected according to the usage of centrifugal pump 10 and the pump ability that is required, and is not limited especially.

As shown in FIG. 1, the blade member 16 is provided with a base edge 18 which extends from the bearing portion 14 in the upward direction of the outer periphery,

an enlarged diameter portion 20, which is enlarged upwardly in the direction of the outer periphery from this base edge 18, and

an outside blade portion 22, which extends from this enlarged diameter portion 20 in direction of outer periphery.

By forming the shape of the blade member 16 to such shape, the discharge ability can be improved by function of the outside blade portion 22 by rotating of the blade member 16.

Moreover, on the rotating blade member 12, a rotor magnet accommodating portion 24 is formed on the outer periphery of bearing portion 14 at the predetermined space and is formed to the outer periphery of the base edge 18.

The rotor magnet accommodating portion 24 is provided with a flange portion 26 which extends downwardly from a lower side of the base edge 18, and a support portion 28 in which a tip of the flange portion 26 is enlarged.

Moreover, to an installation portion 30 which includes these flange portion 26 and support portion 28, a setting hole 32 a of a rotor magnet 32, which includes an annular permanent magnet, is fitted.

As a result, fall of the rotor magnet 32 is prevented by the enlarged support portion 28.

Furthermore, as shown in FIG. 1, the centrifugal pump 10 is provided with a metallic main body casing 34 in which the rotating blade member 12 is accommodated.

The main body casing 34 is provided with an upper main body casing 36.

The upper main body casing 36 comprises a top wall 38 and a side peripheral wall 40 which extends downwardly from an outer periphery of the top wall 38.

Moreover, as shown in FIG. 1, on the side peripheral wall 40 of the upper main body casing 36, a flange 44, in which an opening portion 40 a to fix a metallic suction side coupling member 42 is formed, is formed.

As shown in FIG. 1, on this flange 44, the suction side coupling member 42 (sucking side pipe) is sealingly fixed by, for instance, such as the welding, the soldering and the adhesion.

As a result, the suction side coupling member 42 is connected to the main body casing 34.

Moreover, as shown in FIG. 1, on the side peripheral wall 40 of the upper main body casing 36, to oppose to the opening portion 40 a to fix the suction side coupling member 42, a flange 50, in which an opening portion 40 b to fix a metallic discharge side coupling member 46 (discharge side pipe) is formed, is formed.

In this case, the position of the flange 44 and the flange 50 is not limited, and they can be disposed by shifting the central angle degree (for instance, the central angle degree is shifted 45 degree).

In addition, this shifting angle may not be especially limited, and can be changed by the design change according to the usage etc.

As shown in FIG. 1, on this flange 50, the discharge side coupling member 46 is sealingly fixed by, for instance, such as the welding, the brazing and the adhesion.

As a result, the discharge side coupling member 46 is connected to the main body casing 34.

Moreover, as shown in FIG. 1 and FIG. 2, the main body casing 34 is provided with a lower main body casing 48 (rotor casing).

Moreover, on an inner wall of a lower end 51 of the side peripheral wall 40 of the upper main body casing 36, an outer periphery flange 52 of the lower main body casing 48 is sealingly fixed by, for instance, such as the welding, the brazing and the adhesion.

As a result, as shown in FIG. 3(A), in the main body casing 34, an interior space S1, which is surrounded with the upper main body casing 36 and the lower main body casing 48, is formed.

As shown in FIG. 1, this lower main body casing 48 is provided with a blade accommodating portion 54, which extends horizontally from an outer periphery flange 52 of the lower main body casing 48 to inner periphery side, and a rotor magnet accommodating portion 56, which extends downwardly from this blade accommodating portion 54.

In addition, under this rotor magnet accommodating portion 56, a lower bearing member accommodating portion 58, which has a bottom and is cylindrical shape, is formed.

Moreover, in the lower bearing member accommodating portion 58, a lower bearing member 60 is fitted by, for instance, press fit etc.

In a shaft hole 62 formed on this lower bearing member 60, a lower end portion 66 of an axial member 64 is fixed as pivoted by, for instance, press fit etc. by means of a thrust washer 61.

Moreover, in the bearing portion 14 of this rotating blade member 12, the axial member 64 is passed through so that the rotating blade member 12 can be rotated around.

In addition, as shown in FIG. 1, the main body casing 34 is provided with a blade casing 68.

This blade casing 68, on the side of the suction side coupling member 42, an outer periphery flange 70 of this blade casing 68 is sealingly fixed under the flange 44 of the side peripheral wall 40 of the upper main body casing 36 for instance, by such as the welding, the brazing and the adhesion.

Moreover, the outer periphery flange 70 of blade casing 68 comprises:

a fixing portion 70 a to fix under the flange 44 of the side peripheral wall 40 of the upper main body casing 36, and

an abutting portion 70 b which extends and is curved upwardly in the direction of vertical direction from this fixing portion 70 a.

This abutting portion 70 b extends to the position that abuts to a tip 42 a of the suction side coupling member 42 on the side of the main body casing 34.

Moreover, in this case, the abutting portion 70 b does not extend to the inside diameter portion of the suction side coupling member 42.

As a result, the flow of the fluid from the suction side coupling member 42 is not obstructed.

As a result, the tip 42 a of the suction side coupling member 42 on the side of the main body casing 34 abuts to the abutting portion 70 b of the outer periphery flange 70 of this blade casing 68.

Therefore, the insert position of the suction side coupling member 42 to the opening portion 40 a on the coupling side of the suction side of the side peripheral wall 40 of the main body casing 34 is prescribed.

Therefore, the insert position area of the suction side coupling member 42 to the opening portion 40 a on the coupling side of the suction side of the side peripheral wall 40 of the main body casing 34 is not a shortfall.

As a result, the strength shortfall of the fixing of the suction side coupling member 42 to the flange 44 is not generated.

Moreover, according to this composition, the suction side coupling member 42 is not too much inserted in the opening portion 40 a on the coupling side of the suction side of the side peripheral wall 40 of the main body casing 34.

As a result, the distance between a side peripheral wall 72 of the blade casing 68 is not small.

Accordingly, as described later, the flow of the fluid from the suction side coupling member 42 is never obstructed.

On the other hand, as for the blade casing 68, an opening portion 72 a is formed to the side peripheral wall 72 on the side of the discharge side coupling member 46.

The periphery of the opening portion 72 a of this side peripheral wall 72 is sealingly fixed to the flange 50 of the side peripheral wall 40 of the main body casing 34 together with the discharge side coupling member 46, for instance, by such as the welding, the brazing and the adhesion.

Moreover, the blade casing 68 is provided with a side peripheral wall 72, which extends upwardly from the outer periphery flange 70, and

an extending portion 74, which extends from the side peripheral wall 72 along the outside blade portion 22 of the impeller member 16 in the direction of a horizontally inside.

By having such shape, between the blade accommodating portions 54 of the blade casing 68 and the lower main body casing 48, the blade member 16 can be accommodated.

Moreover, to a protruding portion 38 a, which is projected downwardly to a central portion of the top wall 38 of the upper main body casing 36, an upper bearing member 78 is fixed by a fixing holder 71, so that it is protruded downwardly in an inner periphery side opening portion 74 a of an extending portion 74 of the blade casing 68.

As a result, by the protruding portion 38 a of the top wall 38 of the upper main body casing 36, the upper bearing member 78 is stabilized and is supported.

Therefore, the decentering and the vibration by the rotation of the rotating blade member 12 can be prevented.

On a shaft hole 80 formed to the upper bearing member 78, a top portion 82 of the axial member 64 passed through in the bearing portion 14 of the rotating blade member 12, for instance, by pressing fit, is fixed as pivoted by a thrust washer 73.

Moreover, as shown in FIG. 1, the diameter of the side peripheral wall 72 of the blade casing 68 is formed smaller than the diameter of the side peripheral wall 40 of the upper main body casing 36.

In addition, the height of the side peripheral wall 72 of the blade casing 68 is formed smaller than the height of the side peripheral wall 40 of the upper main body casing 36.

As a result, as shown in FIG. 3(B), by the blade casing 68, the interior space S1, which is formed by the upper main body casing 36 and the lower main body casing 48, is partitioned.

Consequently, a fluid introducing passage 84 is formed on the upper part.

Moreover, a rotating accommodating space S2, in which the rotating blade member 12 is accommodated, is formed on the lower part.

As a result, as shown by arrow A in FIG. 1, the fluid sucked from the suction side fitting member 42 is passed from the fluid introducing path 84, which is formed by the blade casing 68 and the upper main body casing 36, to the inner periphery side opening portion 74 a of the extending portion 74 of blade casing 68.

Moreover, the fluid that passed through the inner periphery side opening portion 74 a is introduced into the rotating accommodating space S2 formed by the blade casing 68 and the lower main body casing 48.

In addition, as shown in FIG. 1, on the outer periphery of the rotor magnet accommodating portion 56 of the lower main body casing 48, a metallic main body casing side fixing bracket 96 which comprises the detaching means, for instance, is fixed by the welding, the brazing, the adhesion, and the press fitting.

This main body casing side fixing bracket 96, as shown in FIG. 1, an engaging portion 98 is formed as curve to the inner periphery side and protruded.

Moreover, as shown in FIG. 1 and FIG. 2, the centrifugal pump 10 is disposed on the outer periphery of the rotor magnet accommodating portion 56 of the lower main body casing 48 to be located in the periphery of the rotor magnet 32.

In addition, a coil portion 104 which rotates the rotating blade member 12 is provided.

As for the coil portion 104, a plurality of coils 110, which comprise a winding wire 108 rolled in a bobbin casing 106, on an electronic substrate 112 to perform an electronic control, though not shown in the drawing, are disposed in the circumferential direction at predetermined spaces.

Moreover, these coils 110 are fitted in a coil installation portion 114 a which is formed in a coil cover main body 114 having a substantially cylindrical shape.

Moreover, the coils 110 are fixed by coil cover 111 having a cover shape to the coil cover main body 114 together with electronic substrate 112.

Moreover, as shown in FIG. 1, on the center section of coil portion 104, an accommodating opening portion 118, in which the rotor magnet accommodating portion 56 and the lower bearing member accommodating portion 58 of the lower main body casing 48 are accommodated, is formed.

Moreover, on the center section of the electronic substrate 112, an accommodating opening portion 112 a, in which the lower bearing member accommodating portion 58 of the rotor magnet accommodating portion 56 of the lower main body casing 48 is accommodated, is formed.

On the other hand, an opening portion 114 b is formed to the center section of the coil cover main body 114.

By this opening portion 114 b, the rotor magnet accommodating portion 56 and the lower bearing member accommodating portion 58 of the lower main body casing 48 are accommodated in the accommodating opening portion 118 of the coil portion 104 and the accommodating opening portion 112 a of the electronic substrate 112.

In addition, as shown in FIG. 1, a coil side fixing protruded portion 116 which comprises the detaching means is provided to the coil cover main body 114.

As for coil side fixing protruded portion 116, as shown in FIG. 1, an engaging piece 124, which is projected from the opening portion 114 b of the coil cover main body 114 upwardly and is projected externally, is formed.

As a result, the engaging portion 98 of the main body casing side fixing bracket 96 is engaged with the engaging piece 124 of the coil side fixing protruded portion 116.

Consequently, the cover coil cover main body 114, in which the coil portion 104 is accommodated and which is covered by coil cover 111, can be provided detachably under the main body casing 34.

In addition, in FIG. 1, the reference numeral 126 shows a connector and 128 shows a lead line and 130 shows a magnetic pole sensor to detect the direction of the rotation and the position where the rotor magnet 32 is rotated.

According to the centrifugal pump 10 like this, the cover coil cover main body 114, in which the coil portion 104 is accommodated and which is covered by coil cover 111, and the main body casing 34 are detachably disposed by a detaching means.

In case of this Embodiment, by means of engagement between the engaging portion 98 of the main body casing side fixing bracket 96 and the engaging piece 124 of the coil side fixing protruded portion 116, it is detachably disposed.

Therefore, before the cover coil cover main body 114, in which the coil portion 104 is accommodated and which is covered by coil cover 111, is fixed to the main body casing 34, for instance, the processing that requires the fixing and heating by heating such as the welding, the brazing, and the adhesion, etc. can be performed to the main body casing 34.

As a result, working ability is improved.

Moreover, the cover coil cover main body 114, in which the coil portion 104 is accommodated and which is covered by coil cover 111, and the main body casing 34 are detachably fixed by the detaching means.

As a result, the exchange when the coil portion 104 is broken down can be easily performed.

In addition, the direction of the draw of the wire and the direction of the coupling (i.e. the suction side coupling member 42 and the discharge side coupling member 46) can be selected arbitrarily.

However, it is not limited in any way as such detaching means.

For instance, other detaching means such as screw engaging and engaging by the convexo-concave can be adopted.

In addition, the axial member 64 of the rotating blade member 12 is pivoted by the upper bearing member 78 and the lower bearing member 60.

As a result, the bearing of the rotating blade member 12 is a stable structure, and an excellent centrifugal pump 10 in durability and silence can be provided.

That is, the rotation of the rotating blade member 12 is stable, the noise when rotating is reduced, and the vibration of the rotating blade member 12 is reduced, and durability is improved.

Moreover, the axial member 64 of the rotating blade member 12 is fixed to the upper bearing member 78 and the lower bearing member 60.

In addition, the rotating blade member 12 is rotated around the outer periphery of axial member 64.

As a result, the rotation sliding area is increased between rotating blade member 12 and the outer periphery of the axial member 64, and the contact surface pressure is reduced.

As a result, the rotation of the rotating blade member 12 is stable, the noise when rotating is reduced, and the vibration of the rotating blade member 12 is reduced, and durability is improved.

In this case, it is desirable that the rotating part between the rotating blade member 12 and the axial member 64, that is, at least, the inner periphery of the bearing portion 14 of the rotating blade member 12 and the outer periphery of the axial member 64, comprise a synthetic resin having a high slidability.

Therefore, the bearing portion 14 of the rotating blade member 12 and the axial member 64 itself may comprise a synthetic resin having a high slidability.

On the other hand, only the inner periphery of bearing portion 14 of rotating blade member 12 and the surface of the outer periphery of the axial member 64 can be covered by such a synthetic resin having a high slidability.

In this case, as for a synthetic resin having a high slidability, it is not especially limited, for instance, the plastic with excellent chemical resistance such as PPS and PTFE can be used.

Like this, as for the rotating part, the synthetic resin having a high slidability is used, so that in the non-lubrication condition in which the bearing is in the fluid, it is excellent in the slidability.

Moreover, the axial member 64 and the rotating blade member 12 are not wear-out and damaged at all by the rotation of the rotating blade member 12.

As a result, durability is improved and neither the rattling nor the eccentricity is caused in the rotating blade member 12.

Consequently, the predetermined and objected pump performance can be retained.

In this case, though not shown in the drawings, the axial member 64 may be fixed to the rotating blade member 12.

Moreover, between the upper bearing member 78 and the axial member 64 and between the lower bearing member 60 and the axial member 64, it is possible that the rotating blade member 12 may be rotated.

By composing like this, the rotation of the rotating blade member 12 is stable, the noise when rotating is reduced, and the vibration of the rotating blade member 12 is reduced, and durability is improved.

In addition, in this case similarly, as for the rotating part between the upper bearing member 78 and the axial member 64 and between the lower bearing member 60 and the axial member 64, the synthetic resin having a high slidability can be used.

The centrifugal pump 10 composed like this is operated as follows.

First of all, the electric current is flowed through the coil 110 of the coil portion 104, so that the coil 110 is excited. As a result, it effects on the rotor magnet 32 of the rotating blade member 12.

Consequently, the rotating blade member 12 can be rotated around the axial member 64, which is passed through the bearing portion 14.

As a result, the blade member 16 of the rotating blade member 12 is rotated.

Consequently, as shown by arrow A of FIG. 1, the fluid sucked from the suction side coupling member 42 is passed from the fluid introducing passage 84, which is formed by the blade casing 68 and the upper main body casing 36, to the inner periphery side opening portion 74 a of the extending portion 74 of the blade casing 68.

Moreover, the fluid passed through the inner periphery side opening portion 74 a is introduced into the rotating accommodating space S2, which is formed by the blade casing 68 and the lower main body casing 48.

In addition, by the turning force of the blade member 16 of the rotating blade member 12, as shown by arrow B of FIG. 1, the fluid introduced into the rotating accommodating space S2 is discharged through the discharge side coupling member 46 from the rotating accommodating space S2 of the main body casing 34.

According to the centrifugal pump 10 composed like this,

the main body casing 34 is a shape, which comprises:

the upper main body casing 36, and

the lower main body casing (i.e. rotor casing) 48 which is fixed to the upper main body casing 36,

the lower main body casing 48 comprising;

the blade accommodating portion 54, which extends horizontally from outer periphery of the lower main body casing 48 to the inner periphery side, and

the rotor magnet accommodating portion 56, which extends downwardly from the blade accommodating portion 54.

Therefore, in the interior space S1 formed between the upper main body casing 36 and the lower main body casing 48 fixed to the upper main body casing 36,

the rotating blade member 12, which includes the impeller member 16 and the rotor magnet 32 provided under the impeller member 16, can be accommodated in compact.

Moreover, the coil portion 104, which is disposed to be located in the periphery of the rotor magnet 32 and in which the rotating blade member 12 is rotated, is provided.

Therefore, the magnetic path is generated by energizing the coil portion 104, which is disposed to be located in the periphery of the rotor magnet 32.

As a result, through the rotor magnet accommodating portion 56 of the lower main body casing 48, it effects to the rotor magnet 32 provided under the impeller member 16.

As a result, stably rotating of the rotating blade member 12 can be attained.

Therefore, the operation loss of the driving motor (the coil portion 104 and the rotor magnet 32) is never caused, and a centrifugal pump which has an excellent pump performance can be provided.

Moreover, the upper main body casing 36 and the lower main body casing 48 that compose a metallic main body casing 34, for instance, can be fixed by heating such as the welding, the brazing, and the adhesion, etc., so that they can be fixed in the sealing state.

That is, it is a structure that joint method with high airtight and maintenance strength such as the welding and the brazing can be applied to these connecting portions.

Therefore, fixing by heating such as the welding, the brazing, and the adhesion, etc. can be applied.

As a result, the centrifugal pump, in which for instance, a refrigerant, a combustible fluid, and the fluid having a toxicity are circulated in the closed circuit, and in which the resisting pressure, airtight, and resistance to corrosion are required, can be provided.

Moreover, the joint portion between the metallic main body casing 34 (the upper main body casing 36 or the lower main body casing 48 or both thereof) and the blade casing 68, for instance, can be fixed by heating such as the welding, the brazing, and the adhesion, etc., so that they can be fixed in the sealing state.

Moreover, the joint portion between the metallic suction side coupling member 42 and the main body casing 34, and the joint portion between the discharge side coupling member 46 and the main body casing 34, for instance, can be fixed by heating such as the welding, the brazing, and the adhesion, etc., so that they can be fixed in the sealing state.

That is, it is a structure that joint method with high airtight and maintenance strength such as the welding and the brazing can be applied to these connecting portions.

Therefore, it can be fixed by heating such as the welding, the brazing, and the adhesion, etc. and the metal casing and the piping having high airtight can be used.

Moreover, the centrifugal pump, in which for instance, a refrigerant, a combustible fluid, and the fluid having a toxicity are circulated in the closed circuit, and in which the resisting pressure, airtight, and resistance to corrosion are required, can be offered.

Moreover, the blade casing 68,

which partitions an interior space S1 formed by the upper main body casing 36 and the lower main body casing 48 so that

a fluid introducing passage 84 is formed at an upper portion, and

a rotating accommodating space S2 that accommodates the rotating blade member 12 is formed at a lower portion,

is provided.

As a result, the path of the fluid can be easily formed.

In this case, it is preferable that the lower main body casing 34 comprises a metallic press molding article, and

the suction side coupling member 42 and the discharge side coupling member 46 comprises the metal pipe.

As a result, joint method with high airtight and maintenance strength such as the welding and the brazing can be applied to these connecting portions.

Moreover, the cost can be reduced.

In this case, it is preferable that the lower main body casing 48 comprises a metallic press molding article, and

the lower main body casing 48 comprises a nonmagnetic metal.

Like this, the lower main body casing 48 comprises a metallic press molding article.

As a result, the lower main body casing 48 (i.e. rotor casing) having the complicated shape,

in which the blade accommodating portion 54 that extends horizontally from outer periphery of the lower main body casing 48 to the inner periphery side, and

in which the rotor magnet accommodating portion 56 that extends downwardly from the blade accommodating portion 54, can be made easily, high-quality, and at a low price.

Moreover, the lower main body casing 48 comprises the nonmagnetic metal.

As a result, the magnetic path (see arrow C of FIG. 2) generated by energizing the coil portion 104, which is disposed to be located in the periphery of the rotor magnet 32, is not obstructed.

Therefore, through the rotor magnet accommodating portion 56 of the non-magnetic lower main body casing 48, it effects on the rotor magnet 32 provided under the impeller member 16.

As a result, stably rotating of the rotating blade member 12 can be attained.

Therefore, the operation loss of the driving motor (the coil portion 104 and the rotor magnet 32) is never caused, and an excellent centrifugal pump 10 in the pump performance can be offered.

In this case, as for the nonmagnetic metal, though it is not especially limited, for instance, copper, stainless steel, aluminum, and brass, etc. are exemplified.

Moreover, it is preferable that such a nonmagnetic metal comprises an austenitic stainless steel.

Thus, if the nonmagnetic metal comprises the austenitic stainless steel, the upper main body casing 36 and the lower main body casing 48 that compose a metallic main body casing 34, for instance, can be fixed by heating such as the welding, the brazing, and the adhesion, etc., so that they can be fixed in the sealing state.

Moreover, if it is the austenitic stainless steel, it is excellent in the drawing property and the mechanical strength.

As a result, the lower main body casing 48 (i.e. rotor casing) having the complicated shape,

in which the blade accommodating portion 54 that extends horizontally from outer periphery of the lower main body casing 48 to the inner periphery side, and

in which the rotor magnet accommodating portion 56 that extends downwardly from the blade accommodating portion 54,

can be made easily by press work, high-quality, and at a low price.

Moreover, the austenitic stainless steel is excellent in the drawing property, so that the thickness of the lower main body casing 48 can be thinned.

As a result, the magnetic path (see arrow C of FIG. 2) generated by energizing the coil portion 104, which is disposed to be located in the periphery of the rotor magnet 32 and which rotates the rotating blade member 12, is not obstructed.

Therefore, through the rotor magnet accommodating portion 56 of the non-magnetic lower main body casing 48, it effects on the rotor magnet 32 provided under the impeller member 16.

As a result, stably rotating of the rotating blade member 12 can be attained.

Therefore, the operation loss of the driving motor (the coil portion 104 and the rotor magnet 32) is never caused, and an excellent centrifugal pump 10 in the pump performance can be offered.

Moreover, the austenitic stainless steel is excellent also in corrosion resistance.

As a result, the centrifugal pump can be offered, in which for instance, a refrigerant, a combustible fluid, and the fluid having a toxicity are circulated in the closed circuit, and in which the resisting pressure, airtight, and resistance to corrosion are required.

In addition, it is preferable that the austenitic stainless steel includes 10.5% or more of the content of nickel.

That is, in case that the lower main body casing 48 (rotor case) having the complicated shape,

in which the blade accommodating portion 54 that extends horizontally from outer periphery of the lower main body casing 48 to the inner periphery side, and

in which the rotor magnet accommodating portion 56 that extends downwardly from the blade accommodating portion 54, is made,

as mentioned above, it is desirable so that the lower main body casing 48 comprises the austenitic stainless steel in order to make it easily, high-quality, and at a low price.

However, for instance, in a usual austenitic stainless steel, such as SUS304 having 8% Ni, which is called 18-8 stainless steel, if the deformation processing is performed such as the drawing etc., the stress induced martensite is generated.

As a result, there is a case that it becomes martensite and is magnetized.

Therefore, the magnetic path (see arrow C of FIG. 2) generated by energizing the coil portion 104, which is disposed to be located in the periphery of the rotor magnet 32 and which rotates the rotating blade member 12, is obstructed, by the lower main body casing 48 that is magnetized.

As a result, the function to the rotor magnet 32 provided under the impeller member 16 is obstructed through the rotor magnet accommodating portion 56 of the lower main body casing 48.

Therefore, the operation loss of the driving motor (the coil portion 104 and the rotor magnet 32) is caused so that the pump performance is decreased.

On the contrary, the austenitic stainless steel includes 10.5% or more of the content of nickel.

As a result, even if the deformation processing is performed such as the drawing etc., the stress induced martensite is not generated easily.

Therefore, it is avoided to become martensite and to be magnetized.

As a result, the magnetic path (see arrow C of FIG. 2) generated by energizing the coil portion 104, which is disposed to be located in the periphery of the rotor magnet 32, is not obstructed.

Therefore, through the rotor magnet accommodating portion 56 of the non-magnetic lower main body casing 48, it effects on the rotor magnet 32 provided under the impeller member 16.

As a result, stably rotating of the rotating blade member 12 can be attained.

Therefore, the operation loss of the driving motor (the coil portion 104 and the rotor magnet 32) is never caused, and an excellent centrifugal pump 10 in the pump performance can be offered.

Moreover, it is preferable that the austenitic stainless steel comprises an austenitic stainless steel having 10.5-16% of the content of nickel.

If the content of the nickel of the austenitic stainless steel is within such the range, even if the deformation processing is performed such as the drawing etc., the stress induced martensite is not generated easily.

Therefore, it is avoided to become martensite and to be magnetized.

As a result, it can be avoided that the function to the rotor magnet 32 provided under the impeller member 16 is obstructed through the rotor magnet accommodating portion 56 of the lower main body casing 48.

Therefore, the operation loss of the driving motor (the coil portion 104 and the rotor magnet 32) is not caused so that the pump performance is not decreased.

If the content of the nickel is below 10.5%, if the deformation processing is performed such as the drawing etc., the stress induced martensite is generated.

As a result, it becomes martensite and is magnetized. Oppositely, if the content of the nickel exceeds 16%, the cost rises since the nickel is expensive.

As for such an austenitic stainless steel having 10.5-16% of the content of the nickel, it is not limited particularly.

However, according to the usage of the centrifugal pump 10, in consideration of the corrosion resistance, the processing, and the mechanical strength, etc., for instance, it may include the austenitic stainless steel selected from SUS305, SUS308, SUS309, SUS316, and SUS317.

In addition, as for the upper main body casing 36, it need not comprise the nonmagnetic metal especially.

Moreover, since it is not a complicated shape like lower main body casing 48, the deformation processing need not be considered like the drawing etc.

Therefore, according to the usage of the centrifugal pump 10, the metallic material may be decided appropriately in consideration of the corrosion resistance, the processing, and the mechanical strength, etc.

Moreover, as for the metallic suction side coupling member 42 and the discharge side coupling member 46, it need not comprise the nonmagnetic metal especially.

Moreover, since it is not a complicated shape like lower main body casing 48, the deformation processing need not be considered like the drawing etc.

Therefore, according to the usage of the centrifugal pump 10, the metallic material may be decided appropriately in consideration of the corrosion resistance, the processing, and the mechanical strength, etc.

For instance, it can be comprise the pipe that includes the copper pipe.

Although preferable embodiment is described above, the embodiments are not limited to this embodiment.

For instance, in the embodiments, the coil portion 104 is accommodated in the coil cover main body 114, and it is covered by the coil cover 111.

However, the coil portion 104 can be molded with the molding resin, and this coil portion 104 can be provided under the main body casing 34 detachably.

In addition, in the Embodiment, the number of the suction side coupling member 42 and the discharge side coupling member 46 is assumed to be one piece respectively.

However, the number of suction side coupling member 42 and discharge side coupling member 46 can be plurality.

Therefore, various changes are possible in the scope in which it does not deviate from the objects.

INDUSTRIAL APPLICABILITY

The centrifugal pump can be applied to circulate the fluid in the closed circuit, for instance, refrigerant used for refrigerant circulation circuits such as air conditioners and freezers, and cooling water etc. used for cooling circulation circuits such as parts and apparatuses that generate heat.

Moreover, this centrifugal pump is a centrifugal pump in which the resisting pressure and airtight environment are required.

An excellent centrifugal pump as to the pump performance may be provided.

In the centrifugal pump, it can be fixed by heating such as welding, brazing, and adhesion, etc. and the metal casing and the piping having a high airtight environment can be used.

Moreover, the centrifugal pump can be used as the centrifugal pump, in which for instance, a refrigerant, a combustible fluid, and the fluid having toxicity are circulated in the closed circuit, and in which the resisting pressure, airtight, and resistance to corrosion are required.

Explanation of Letters or Numerals

-   10 Centrifugal pump -   12 Rotating blade member -   14 Bearing portion -   16 Impeller member -   18 Base edge -   20 Enlarged diameter portion -   22 Outside blade portion -   24 Rotor magnet accommodating portion -   26 Flange portion -   28 Support portion -   30 Installation portion -   32 Rotor magnet -   32 a Setting hole -   34 Main body casing -   36 Upper main body casing -   38 Top wall -   38 a Protruding portion -   40 Side peripheral wall -   40 a Opening portion -   40 b Opening portion -   42 Suction side coupling member -   42 a Tip -   44 Flange -   46 Discharge side coupling member -   48 Lower main body casing -   50 Flange -   51 Bottom -   52 Outer periphery flange -   54 Blade accommodating portion -   56 Rotor magnet accommodating portion -   58 Lower bearing member accommodating portion -   60 Lower bearing member -   61 Thrust washer -   62 Shaft hole -   64 Axial member -   66 Lower end portion -   68 Blade casing -   70 Outer periphery flange -   70 a Fixing portion -   70 b Abutting portion -   71 Fixing holder -   72 Side peripheral wall -   72 a Opening portion -   73 Thrust washer -   74 Extending portion -   74 a Inner periphery side opening portion -   78 Upper bearing member -   80 Shaft hole -   82 The top portion -   84 Fluid introducing passage -   96 Main body casing side fixing bracket -   98 Engaging portion -   104 Coil portion -   106 Bobbin casing -   108 Winding wire -   110 Coil -   111 Coil cover -   112 Electronic substrate -   112 a Accommodating opening portion -   114 Coil cover main body -   114 a Coil installation portion -   114 b Opening portion -   116 Coil side fixing protruded portion -   118 Accommodating opening portion -   124 Engaging piece -   126 Connector -   128 Lead line -   130 Magnetic pole sensor -   A Arrow -   B Arrow -   C Arrow -   S1 Interior space -   S2 Rotating accommodating space 

What is claimed:
 1. A centrifugal pump comprising: a rotating blade member including an impeller member and a rotor magnet provided under the impeller member, a metallic main body casing in which the rotating blade member is accommodated, and a coil portion configured to rotate the rotating blade member, wherein the coil portion is disposed to be located in a periphery of the rotor magnet, the metallic main body casing including; an upper main body casing, and a lower main body casing which is fixed to the upper main body casing, the lower main body casing including; a blade accommodating portion, which extends horizontally from an outer periphery of the lower main body casing to an inner periphery side, and a rotor magnet accommodating portion, which extends downwardly from the blade accommodating portion.
 2. The centrifugal pump of claim 1, wherein the lower main body casing includes a metallic press molding article, and the lower main body casing includes a nonmagnetic metal.
 3. The centrifugal pump of claim 2, wherein the nonmagnetic metal includes an austenitic stainless steel.
 4. The centrifugal pump of claim 3, wherein the austenitic stainless steel includes 10.5% or more of the content of nickel.
 5. The centrifugal pump of claim 3, wherein the austenitic stainless steel includes 10.5-16% of the content of nickel.
 6. The centrifugal pump of claim 5, wherein the austenitic stainless steel comprises one of SUS305, SUS308, SUS309, SUS316, or SUS317.
 7. The centrifugal pump of claim 1, further comprising: a metallic suction side coupling member, which is provided to connect to the metallic main body casing to introduce fluid into the impeller member, a metallic discharge side coupling member, which is provided to connect to the metallic main body casing to exhaust at least a part of fluid by rotating the impeller member, and a blade casing, which partitions an interior space formed by the upper main body casing and the lower main body casing so that a fluid introducing passage is formed at an upper portion, and a rotating accommodating space that accommodates the rotating blade member is formed at a lower portion. 